A. Field of the Invention
The present invention is related to systems for discouraging non authorized changes or the removal of identification labels from a product, and more particularly to a label including a device for discouraging the unauthorized removal of the label from a product, which destroys the information contained in the label and/or destroy its microchip if included.
B. Description of Related Art
For identification applications, it's very common the use of identification cards which adhere to the surface of a product to be identified or described. In some applications the card may be removed form the product in order to be adhered to other product for illegal purposes.
The development of new technologies for the protection of documents has been traditionally oriented towards the label and identification cards made by multilayer lamination.
The French patent No. FR-A-2451081 discloses a system in which one of the layers comprising an identification label, contains a plurality of micro-capsules filled with ink, in this way, when it is attempted to separate one layer from another, some of the micro-capsules broke thus permanently staining the label with ink and indicating that an attempt for breaking or removing the label has been perpetrated. However this system is not suitable for using with identification means which are not visually inspected such as magnetic, electromagnetic or radio-frequency devices.
Another type of protection systems, include zones with different adhesion coefficients over one of the layers comprising a multilayer label, which cause that during the separation of the layers, the layer containing information printed in one of the layers contacting the zones with higher adherence coefficient be ripped and damaged, such as the systems described in the patents Nos. U.S. Pat. Nos. 4,876,123, 5,082,702, 5,629,093, and DEA 36 08 907. However this multilayer system is neither suitable for using with identification means which are not visually inspected, such as those that are read or identified by electronic means.
An improvement over the above referred systems would be the incorporation of a heat deformable layer (as disclosed in U.S. Pat. No. 6,284,337) which avoids the separation of the layers by softening the adhesive with heat.
Regarding to the protection of labels including an electronic circuit, some systems suggest the application of a high resistance adhesive in certain sections of a layer in contact with certain sections of the chip in such way that when someone try to remove the label, the layer having the high resistance adhesive pull up and rip some zones of the chip make it useless, such as the system disclosed in U.S. Pat. No. 6,049,145. However, there is the possibility of fixing the circuit by welding or reconnecting the damaged zones of the circuit,
In order to avoid the unauthorized copy of electronic circuits, there has been proposed the use of covers over the circuits such as the cover disclosed in U.S. Pat. No. 5,916,944, so that when there is an attempt for analyzing the circuit structure, a polymerization action is activated which covers the circuit and avoids the circuit analysis, although the circuit remains fully functional, which is a disadvantage.
Therefore it would be desirable to have a security device for identification labels that completely destroys the i information and circuitry contained in said label in case an unauthorized attempt to remove the label is perpetrated thus making the label completely useless and beyond repair.
In view of the above referred necessities and disadvantages of the systems of the prior art, applicant developed a system for discouraging that labels permanently adhered to a surface be removed and reused. Applicant's system contains an activator substance that reacts with an oxidant and starts a combustion which permanently damages the label when it is attempted to remove the label from a surface. If the destruction of a specific element that can not be affected by the combustion is needed, the system includes an element that raises the temperature in specific sections of the label.
The system of the present invention comprises in its most general embodiment:
When it is attempted to remove the base card from the surface, the mechanical forces will tear any of the spheres or activator container and starts an uncontrollable combustion reaction that permanently damages the first, second and third layers.